This section provides background information related to the present disclosure which is not necessarily prior art.
Electromagnetic spectrum filters, such as color filters, are an important component for various display technologies, including flat panel displays, liquid crystal displays, projection displays, eye-wear displays, complementary metal-oxide-semiconductor (CMOS) image sensors, light emitting diodes, and the like. For example, transmission-type optical spectrum filters are widely utilized in applications such as liquid crystal display (LCD) panels. Conventional optical filters use pigment dispersions to produce red-green-blue (RGB) colors by absorbing complementary colors. Colored pigments also form the basis for most of the colored prints widely used in the printing industry.
However, such conventional optical pigment-based filters and colored print are manufactured by four separate processes, which not only complicates the manufacturing process and increases cost, but also wastes significant chemical materials in the process. For display and imaging applications, while Fabry-Perot based etalon color filters have been proposed, the conventional Fabry-Perot based filter still presents issues regarding undesirable angle dependence, meaning that the filtered light wavelength exiting the filtering device suffers from a significant shift of wavelength and therefore color shift, depending upon the viewing angle. Such angle dependence is undesirable in various imaging and display applications.
Accordingly, there is a need for a new spectrum filter technology, like a color filter, that can produce optical filters in the visible or near infrared range, for example, with high transmission efficiency and with minimal angle dependence, as well as reduced manufacturing complexity.